Medication injection or infusion sets are generally well known in the art, to include a relatively soft and flexible cannula providing a transcutaneous pathway through which a selected medication or other therapeutic fluid can be administered to a patient at a selected subcutaneous site. In a common form, the soft cannula is carried by a housing initially assembled with an insertion needle extending through the cannula, wherein the insertion needle is manipulated to pierce the patient's skin to place the cannula transcutaneously, followed by withdrawal of the insertion needle to leave the soft cannula in place on the patient. In order to allow the insertion needle to be handled, the needle is normally provided as an insertion device comprising a hub to which the needle is attached.
The selected medication may then be coupled to the cannula, typically by means of a length of infusion tubing connected to a medication source to deliver the medication through the cannula to the patient.
In one configuration, the infusion tubing is connected to the cannula housing corresponding to the opening through which the insertion needle has been withdrawn from the cannula, i.e. the tubing is arranged axially with respect to the general axial orientation of the cannula. An example of this type of infusion device is disclosed in U.S. Pat. No. 6,056,718.
In a second configuration, the infusion tubing is connected to the cannula housing at a location different from the opening through which the insertion needle is inserted into the cannula, this configuration allowing the tubing to be pre-connected to the housing. An example of this type of infusion device is known from WO 00/03757 and U.S. Pat. No. 5,545,143 both disclosing a device in which the cannula and insertion needle are arranged perpendicular to tubing. In order to seal the device, a self-sealing penetratable septum is provided corresponding to the opening through which the insertion needle is withdrawn, this septum also allowing samples to be taken without having to disconnect the tubing.
The use of insertion needles, or needle devices in general, is associated with some disadvantages during use thereof due to the potential danger of exposure to the pointed tip before use as well as after the needle has been withdrawn and before it has been properly discarded. Correspondingly, a large number of needle protection devices have been proposed to provide a remedy to this problem.
A very simple form of protection is the traditional tubular sleeve which normally covers the needle when supplied to the user, for example as shown in U.S. Pat. No. 5,545,143; after use the cover may be used to cover the needle again, however, in most cases the needle and the cover are discarded separately A more elaborate shell-shaped needle guard is disclosed in U.S. Pat. No. 6.056,718, however, basically this guard functions as a simple needle cover to be removed from the insertion device prior to use.
In order to better protect against unintended needle prick, a number of shield devices has been proposed based on the principle that a pivotable shield is mounted corresponding to the front of the device, this allowing the shield to be pivoted away before use of the needle as well as used to cover the needle immediately after use, An example of this type of needle protection device is disclosed in U.S. Pat. No. 5,011,475.
For the above-described type of infusion devices in which an insertion needle is arranged through a cannula, different solutions have been proposed. For example, a recent type of needle protection devices is based upon the principle that a protecting means automatically grips the needle tip as the insertion needle is withdrawn from the infusion device, however, this solution requires a separate cover to protect the needle prior to use,
A different approach is known from WO 00/03757 disclosing an infusion device in which an insertion needle hub is provided with a hinged shield member protruding there from, whereby the shield member is adapted to pivot and thereby cover the insertion needle when withdrawn from the infusion device. Also this solution requires a separate cover to protect the needle prior to use.